Suppose a kind of vegetables are loaded with X cars, B kinds of vegetables are loaded with Y cars, and C kinds of vegetables are loaded with Z cars.

{X+Y+Z=20

{2X+Y+ 1.5Z=36

{ 2X * 500+Y * 700+ 1.5Z * 400 = 18300

Solution:

{X= 15

{Y=3

{Z=2

A: Car A 15, car B 3 and car C 2.